SEARCH FOR RADIO COUNTERPARTS OF GRAVITATIONAL-WAVE EVENTS DETECTED BY LIGO/VIRGO EXPERIMENTS IN THE DATA OF DAILY SURVEY OF BSA LPI AT 110 MHZ

Abstract

Purpose: One of the most interesting goals for astronomers are multi-range observations of space objects – not only in different spectral ranges, but also using other sources of information, for example, studies of objects emitting gravitational waves. Design/methodology/approach: The BSA LPI (Big Scanning Antenna of Lebedev Physical Institute) radio telescope has a multi-beam diagram and is capable of recording daily in the frequency range 109–111.5 MHz in 96 beams in the declination range from -8° to +42° daily logs 87.5 GB of data (32 TB per year). The number of frequency bands is within 6 to 32 for the time constant from 0.1 to 0.0125 s. Findings: One of the scientific tasks in processing the data obtained is to search for responses to extragalactic transient events, which a priori should have large dispersion delays (DM ~ 100-2000 pc ·cm -³). Such events include fast radio bursts (FRB) detected so far only at frequencies of 1 GHz and higher, afterglow of nearby cosmic gamma-ray bursts (GRB), in the gamma and X-ray bands, and, finally, possible electromagnetic counterparts of gravitational-wave events recorded in the LIGO-Virgo experiments. The last ones are taken in this paper as a basis for perfection of the technique of searching the like events from the BSA radio data. We provide a brief description of the methodology for finding and estimating the upper limits of possible transient radio sources accompanying the gravitational wave events GW150914, GW151226, LVT151012, and GW170104 recorded by the LIGO detectors. Сonclusions: It is established that nothing brighter than 50000 Jy in the northern hemisphere of the sky at 110 MHz was not observed at the moment of gravitational events. The estimates of energy release in the long-wave radio range are also made: the energy of the low-frequency range is ≤ 1044 erg, while the ratio of the low-frequency range energy to the energy of the gravitational event is ≤10-10.

Keywords

• radio observation
• gravitational event
• search technique